1. Field of the Invention
The present invention relates to building climate control systems in general, and particularly to a building climate control system adapted to control air quality.
2. Background of the Prior Art
In a typical climate control system of a building, a central thermostat controls the temperature of air in the building. A building's central heating/cooling unit forces hot air or cool air to various points in a building through a ductwork comprising a supply air duct, a plurality of zone ducts, and a return air duct.
In many climate control systems, equal amounts of air are forced into each zone of a building through each zone duct. This type of system sometimes leads to temperature imbalances in a building, for example, in the case where intense sunlight shines for extended periods of time on one side of a building.
In one modern climate control system, temperature is controlled on a zone by zone basis. The amount of air that is forced through a given zone duct depends on the temperature, demand of the zone, and the overall temperature demand of the system.
While currently available building climate control systems regulate temperature in a building, and sometimes regulate temperature on a zone by zone basis, they generally do not take into account air quality. Air quality shall herein refer to any measurable non-temperature characteristic of air in a building having a determinable satisfactory range of levels or concentrations, and a determinable non-satisfactory range of levels or concentrations. Air quality can be measured in terms of carbon dioxide concentration. When a room in a building becomes heavily populated, the room's air quality declines as evidenced by an increase in the air's carbon dioxide concentration.
There exists a need for building a climate control system which can control the quality of air in a building.